To mitigate the global warming problem, use of non-polluting, renewable and sustainable energy becomes necessary. Solar energy is one type of the desirable renewable energy.
The most popular application of solar energy is grid-tied solar system. It connects to the electric power grid. The two main components of such system are the solar modules and the solar power converter. A grid-tied solar power system has the main objective of extracting as much energy as possible from the solar modules when sunlight impinges on them while maintaining acceptable power quality, reliability and cost-competitiveness. However, achieving this objective is fraught with many challenges such as low conversion efficiency of the system, intermittency and variability nature of solar energy, Load variations and high cost of system. Adding an energy storage battery in such system mitigates some of these challenges, as it provides stored energy during nights, resulting in minimizing solar energy intermittency and variability effects and reducing customers' utility bills.
The techniques disclosed in U.S. Pat. Application US 2011/0210694 A1 and U.S. Pat. No. 5,522,944 represent the prior art of solar energy system with storage battery technology. These systems suffer three major deficiencies: (1) low battery charging efficiency because it requires two stages of power conversions (DC-AC and AC-DC); (2) long battery charging time because its battery charger is limited to low power charger due to cost; the typical battery recharging time is in several hours compared to in several minutes by a high power charger; thus, it cannot charge or discharge storage battery several times during the day to maximize the solar energy use; even if a separate high power battery charger is installed with a high cost, it still has very low battery charging efficiency as indicated in (1) above; (3) lack of optimal energy management control method for varying load power because it cannot quickly charge/discharge storage battery several times during the day. Therefore, a solar energy system with a high power single stage battery super charger system along with optimal energy management control method is best solution for the future solar energy system.
The prior art has not set forth a low cost and high efficiency solar energy system and method that can maximize solar energy usage and consume less grid power. The object of this invention is to provide a solar energy conversion system with a built-in high power storage battery super charger/discharger system and an optimal energy management control method to maximize solar energy usage by extend sun peak hour resulting in consuming less grid power.